The Lava Eel is a fish that can be found during all times and seasons in the Mines and the Forge. It is the only fish that can spawn in lava. Other than Legendary Fish, it is the second most difficult fish (after Octopus) to catch and the fish with the highest sell price.
Lava Eels can be placed in a Fish Pond, where they will reproduce every 5 days. The initial pond capacity is 1 fish, but the capacity can be increased to 10 by completing four quests. After the first quest is completed, the color of the pond water changes to red. The primary output is red Lava Eel Roe, but Gold Ore is possible starting at population 3 and several more valuable items are possible starting at population 9.